Because they give off absolutely no light and no radiation. The only radiation is X-Rays from the stars being sucked in.
you go to a hole that's black and tell people about it.
While black holes give off radio waves, the fact that no light can escape, or be reflected off of, black holes makes them completely invisible to any regular light-capturing device.
Black holes emit Hawking Radiation, which is the only way of locating one from a great distance
Black holes are a bit hard to detect, so I am pretty sure that not all black holes in this galaxy are known - and I suspect there is not even a decent estimate. But you can expect there to be several.
Black holes do exist - they are just VERY difficult to detect.
no dude, the evidences of the existence of black holes is now widely accepted and i believe that black holes rules our universe but it is difficult to find them because black holes are nearly the perfectly black bodies
Primordial black holes are thought to have formed in the early universe due to fluctuations in density. These black holes are believed to be small and have a range of masses. They are not formed from the collapse of massive stars like regular black holes. Primordial black holes are difficult to detect because they do not emit light. Scientists are still studying these mysterious objects to better understand their formation and characteristics.
It is difficult to ask black holes about how they are involved in active galaxy research because they cannot talk, this makes them only peripherally involved in understanding active galaxies
Professor Stephen Hawking knows a bunch of facts about black holes. The count would be too difficult to quantify and probably not as interesting as the information itself.
An intermediate-mass black hole is one with a mass significantly greater than the typical stellar-mass black holes, but less than the supermassive black holes such as are found at galactic centers. Their identification remains difficult, and their origins remain in the realm of speculation, although a reasonable theory hints at the likelihood of their formation from accretion of dense stellar clusters... and one possibly is that they are primordial black holes left over from the creation of the universe.
stellar black holes were stars (these are large)primordial black holes were pieces of the big bang (these are microscopic)
The lack of direct evidence for black holes poses a challenge for scientists because black holes, by their nature, do not emit any light or radiation that can be easily detected. Instead, researchers must rely on indirect observations and theoretical models to infer the presence of black holes. This makes it difficult to conclusively prove their existence through direct observation.